1. Field of the Invention
The present invention relates to new derivatives of the antibiotic XK-62-2, their acid addition salts, and a process for preparing the same.
2. Description of the Prior Art
XK-62-2, a known antibiotic described in copending U.S. Patent Application Ser. No. 364,058, filed May 25, 1973, now abandoned, is represented by the formula: ##STR1## Antibiotic XK-62-2-and processes for producing the same are also set forth in Okachi et al, the Journal of Antibiotics, Vol. XXVII, No. 10, pages 793-800, 1974.
Briefly stated, as disclosed in the aforementioned U.S. Patent Application Ser. No. 364,058 (the disclosure of which is hereby expressly incorporated herein by reference), antibiotic XK-62-2 is readily produced by culturing actinomycetes such as Micromonospora sagamiensis. More specifically, strains of the above-mentioned microorganisms such as Micromonospora sagamiensis ATCC 21826, ATCC 21827, ATCC 21803 and ATCC 21949 are inoculated into a liquid medium containing a carbon source which the microorganism can utilize such as sugars, hydrocarbons, alcohols, organic acids, etc.; inorganic or organic nitrogen sources and inorganic salts and growth promoting factors and are cultured at 25.degree.-40.degree. C. for 2 to 12 days until substantial anti bacterial activity is detected in the culture liquor. Isolation and purification of XK-62-2 is carried out by a combination of adsorption and desorption from ion exchange resins and active carbon and column chromatography using cellulose, Sephadex, alumina and silica gel. In this manner, XK-62-2 can be obtained in the form of a salt or as a free base.
XK-62-2 has a molecular formula of C.sub.20 H.sub.41 N.sub.5 O.sub.7, and a molecular weight of 463. The substance is freely soluble in water and methanol, slightly soluble in ethanol and acetone and insoluble in chloroform, benzene, ethyl acetate and n-hexane.